JP2020179314A - Regenerant feeder and ultra-pure water production apparatus - Google Patents

Abstract

To provide a regenerant feeder with minimum impact from elution of metal components.SOLUTION: A regenerant feeder 3 that feeds a regenerant for regenerating a cation-exchange resin to an ion exchange resin tower 2 filled with the cation-exchange resin is installed outdoor, having a tank 10 for reserving the regenerant, a piping 20 for connecting the tank 10 to the ion exchange resin tower 2, and temperature control mechanisms 13 and 23 for controlling the temperature of the regenerant fed to the ion exchange resin tower 2 from the tank 10 through the piping 20.SELECTED DRAWING: Figure 1

Description

The present invention relates to a regenerating agent supply device and an ultrapure water production device.

In the manufacturing process of semiconductor devices and liquid crystal devices, ultrapure water from which impurities are highly removed is used as a cleaning liquid for cleaning electronic components such as semiconductor wafers and glass substrates. Ultrapure water is generally produced by sequentially treating raw water (river water, groundwater, industrial water, etc.) with a pretreatment system, a primary pure water system, and a secondary pure water system (subsystem). In such an ultrapure water production apparatus, it is known that metal components are eluted from the pipes and pumps used, which causes deterioration of the water quality of the ultrapure water. In particular, in recent years, with the increasing integration and miniaturization of semiconductor devices, ultrapure water having a metal concentration of pg / L level has been required, and it has been required to reduce the elution amount of metal components as much as possible. There is. On the other hand, some measures for minimizing the influence of elution of metal components have been proposed (see, for example, Patent Documents 1 and 2).

Japanese Unexamined Patent Publication No. 2004-154713 Japanese Unexamined Patent Publication No. 2011-224489

Some of the primary pure water systems and subsystems described above are equipped with an ion exchange resin tower filled with an ion exchange resin, and a regenerator that regenerates the ion exchange resin is further added to the ion exchange resin tower. Some are equipped with a regenerator supply device to supply. In such a regenerating agent supply device, a rubber lining is provided on the inner surface of a tank for storing the regenerating agent and a pipe for transporting the regenerating agent in order to suppress elution of metal components due to the regenerating agent such as acid or alkali. Is common. However, even so, the water quality of ultrapure water may be affected by the elution of metal components, and the cause is not clearly understood at present.

Therefore, an object of the present invention is to provide a regenerator supply device and an ultrapure water production device that minimize the influence of elution of metal components.

In order to achieve the above-mentioned object, the regenerating agent supply device of the present invention supplies a regenerating agent for regenerating a cation exchange resin to an ion exchange resin tower filled with a cation exchange resin, and outdoors. It has a tank that is installed and stores the regenerant, a pipe that connects the tank and the ion exchange resin tower, and a temperature control mechanism that controls the temperature of the regenerant supplied from the tank to the ion exchange resin tower through the pipe. ing.

Further, the ultrapure water production apparatus of the present invention includes an ion exchange resin tower in which a cation exchange resin is filled therein, and the regenerator supply apparatus described above.

According to such a regenerating agent supply device and an ultrapure water production device, by controlling the temperature of the regenerating agent, it is possible to suppress the elution of metal components from the tank or piping that may occur due to the high temperature of the regenerating agent. be able to.

As described above, according to the present invention, the influence of elution of metal components can be minimized.

It is a schematic block diagram of the ultrapure water production apparatus which concerns on 1st Embodiment of this invention. It is a graph which shows the result of having measured the change of the elution amount of a metal component from a lining material when the temperature of a regenerating agent was changed. It is a schematic block diagram of the tank in the regenerant supply apparatus which concerns on 2nd Embodiment of this invention. It is a schematic block diagram of the ultrapure water production apparatus which concerns on 3rd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present specification, the regenerant supply device of the present invention will be described by exemplifying a case where it is used for regenerating an ion exchange resin (cation exchange resin) in an ultrapure water production device, but a semiconductor device or a liquid crystal device. It is also suitably used as a cleaning liquid supply device that supplies a cleaning liquid (acid) in the manufacturing process of.

(First Embodiment)
FIG. 1 is a schematic configuration diagram of an ultrapure water production apparatus according to a first embodiment of the present invention.

The ultrapure water production apparatus 1 produces ultrapure water by sequentially treating water to be treated, and has an ion exchange resin tower 2 filled with a cation exchange resin. The ion exchange resin tower 2 constitutes a primary pure water system or a secondary pure water system (subsystem) of the ultrapure water production apparatus 1, and mainly has a function of removing metal ions (for example, calcium ions) in the water to be treated. have. It should be noted that the illustration of other devices (various membrane filtration devices, ultraviolet oxidation devices, electric deionized water production devices, etc.) constituting the primary pure water system or subsystem is omitted here.

Further, the ultrapure water production apparatus 1 is an acid (for example, hydrochloric acid) which is a regenerating agent for regenerating the cation exchange resin when the ion exchange group of the cation exchange resin is saturated and the processing performance of the ion exchange resin tower 2 deteriorates. It has a regenerator supply device 3 that supplies the ion exchange resin tower 2 (such as sulfuric acid). The regenerating agent supply device 3 is installed outdoors and has a tank 10 for storing the regenerating agent and a pipe 20 for connecting the tank 10 and the ion exchange resin tower 2. The tank 10 is made of a lightweight, high-strength, corrosion-resistant material, for example, fiber reinforced plastic (FRP), and its inner surface is lined with an acid-resistant material. The pipe 20 is made of vinyl chloride, for example, and its inner surface is lined with an acid-resistant material like the tank 10. Examples of the lining material used here include natural hard rubber and butyl rubber.

By the way, especially in the summer when the influence of the outside air temperature and the direct sunlight is large, the outer surface of the tank 10 installed outdoors becomes hot, and the regenerant inside the tank 10 may also become hot. Further, although the regenerating agent is retained inside the pipe 20, the amount of the regenerating agent is smaller than that of the regenerating agent inside the tank 10, so that it is more easily affected by the outside air temperature and direct sunlight. It can get hot. In the present embodiment, in order to block the heat of the outside air and appropriately control the internal temperature of the tank 10 and the pipe 20, heat shield materials 13 and 23 are provided in the tank 10 and the pipe 20, respectively. Specifically, the tank 10 has a double wall structure composed of an inner wall 11 and an outer wall 12, and a heat shield material 13 is arranged in a gap between the inner wall 11 and the outer wall 12. Further, the pipe 20 also has a double pipe structure composed of an inner pipe 21 and an outer pipe 22, and a heat shield material 23 is provided in a gap between the inner pipe 21 and the outer pipe 22. As the material of the heat shield materials 13 and 23, urethane foam is preferably used because it has acid resistance. Further, urethane foam is lightweight and has excellent workability, and is also preferable in that it can be easily installed by simply filling the gap and then curing it.

In such installation of the heat shield materials 13 and 23, when the temperature of the regenerating agent is not properly controlled and the temperature of the regenerating agent rises, the amount of metal components eluted from the lining provided on the inner surfaces of the tank 10 and the pipe 20. Is based on the finding that The experimental results that led to this finding will be described below.

The present inventors measured the change in the amount of metal components eluted from the lining material when the temperature of the regenerating agent was changed. Specifically, a small plastic bottle (polyethylene bottle) is prepared, and a lining material and 1N hydrochloric acid are sealed in the bottle, and these are placed in an environment of normal temperature (23 ° C) and high temperature (60 ° C), respectively. After storage for 20 hours, the concentration of various metals contained in the removed hydrochloric acid was measured. Natural hard rubber was used as the lining material, and the metal concentration was measured using an inductively coupled plasma emission spectrometer.

FIG. 2 is a graph showing the measurement results of various metal concentrations, and shows the ratio of various metal concentrations at high temperature when the various metal concentrations at room temperature are set to 100%. As is clear from this figure, it was confirmed that the metal concentration at high temperature was higher than that at room temperature in all the measured metals. This indicates that as the temperature of hydrochloric acid in contact with the lining material increases, the amount of metal components eluted from the lining material increases.

From this point of view, as described above, in the present embodiment, the heat shield materials 13 and 23 that thermally shield the inside of the tank 10 and the pipe 20 from the outside are provided, respectively. The heat shields 13 and 23 function as a temperature control mechanism for controlling the temperature of the regenerating agent supplied from the tank 10 to the ion exchange resin tower 2 through the pipe 20, so that the regenerating agent does not become excessively hot. The temperature can be controlled appropriately. As a result, the elution of metal components from the lining provided on the inner surface of the tank 10 and the pipe 20 that may occur when the regenerant becomes hot is suppressed, and the ultrapure water produced by the ultrapure water production apparatus 1 is suppressed. It becomes possible to reduce the metal concentration in the water as much as possible.

In the present embodiment, the heat shield materials 13 and 23 are arranged in the gap of the double wall structure of the tank 10 and the gap of the double pipe structure of the pipe 20, respectively, but the method of installing the heat shield material is limited to this. It's not something. For example, the heat shield material may be arranged so as to cover the outer circumference of the tank, or may be arranged so as to cover the outer circumference of the pipe. This makes it possible to install the heat shield material in the existing tank or piping, and it becomes possible to additionally control the temperature of the regenerating agent in the existing regenerating agent supply device. It is preferable to use urethane foam as the heat shield as described above, because it is easy to install in such an existing regenerator supply device.

Further, in the illustrated example, the heat shield material 23 is installed in the portion of the pipe 20 exposed to the outside, but the heat shield material 23 may be installed over the entire range of the pipe 20. For example, when the ion exchange resin tower 2 is installed outdoors and the pipe 20 is also installed outdoors, it is preferable that the heat shield 23 is installed over the entire range of the pipe 20.

(Second Embodiment)
FIG. 3 is a schematic configuration diagram of a tank in the regenerator supply device according to the second embodiment of the present invention. This embodiment is a modification of the first embodiment, and is a modification in which the configuration of the tank in the regenerator supply device is changed. Therefore, in the following, only the configuration of the tank of the present embodiment will be described.

In the present embodiment, as a temperature control mechanism for controlling the temperature of the regenerant inside the tank 10, an air flow means 30 for circulating air between the inner wall 11 and the outer wall 12 of the tank 10 is provided. The air flow means 30 is provided in the air inlet 31 provided in the lower part of the tank 10, the air outlet 32 provided in the upper part of the tank 10, and the hollow portion S between the inner wall 11 and the outer wall 12, and is provided in the air inlet. It has a rectifying plate 33 that forms a spiral passage that communicates the 31 and the air outlet 32.

With such an air flow means 30, even when the air in the hollow portion S becomes hot due to the influence of the outside air temperature or direct sunlight, for example, such air is moved to the upper part of the tank 10 to the outside. It becomes possible to appropriately control the temperature of the regenerant in the tank 10. A blower or the like may be installed at the air inlet 31 or the air outlet 32 to forcibly introduce air into the hollow portion S, but since a separate power supply for that purpose is required, the air is forcibly introduced. In this case, for example, it is preferable to introduce the conditioned air in the building where the ion exchange resin tower 2 is installed by using a duct or the like.

As a temperature control mechanism for the regenerant, water cooling may be considered, but for that purpose, it is necessary to install a pipe in the hollow portion S of the tank 10, which may lead to an increase in cost and weight of the tank 10. It is also necessary to take measures against water leakage due to deterioration over time. Further, not only a pump for circulating the cooling water is required, but also a large amount of cooling water is required because the tank 10 used in the present embodiment has a very large capacity of 10,000 L or more. From such a viewpoint, it is preferable to control the temperature of the regenerating agent inside the tank 10 by circulating the air in the hollow portion S as in the present embodiment.

(Third Embodiment)
FIG. 4 is a schematic configuration diagram of an ultrapure water production apparatus according to a third embodiment of the present invention. This embodiment is an embodiment that can be additionally applied to the first and second embodiments. Therefore, although the description thereof is omitted, the heat shield material of the first embodiment and the second embodiment The air flow means of the above may be provided in the regenerator supply device of the present embodiment.

The regenerating agent supply device 3 of the present embodiment has a heat exchanger 41, a temperature sensor 42, and a drain valve (drainage means) 43 as a temperature control mechanism for the regenerating agent. The heat exchanger 41 is provided in the pipe 20 in the building where the ion exchange resin tower 2 is installed, specifically, near the boundary between the building and the outside, and has a function of cooling the regenerator. The temperature sensor 42 is provided on the downstream side of the heat exchanger 41 in the pipe 20, and has a function of detecting the temperature of the regenerating agent flowing in the pipe 20. The drain valve 43 is provided further downstream than the temperature sensor 42, and has a function of discharging the regenerating agent flowing in the pipe 20 to the outside based on the detection result of the temperature sensor 42. Specifically, the drain valve 43 discharges the regenerating agent to the outside (for example, an acid neutralization tank) when the temperature of the regenerating agent is equal to or higher than a predetermined temperature, and when the temperature of the regenerating agent is lower than the predetermined temperature. , The regenerating agent is supplied to the ion exchange resin tower 2 as it is.

In the ultrapure water production apparatus 1, the same lining is applied to the wetted surfaces of members other than the tank 10 and the pipe 20, and the contact with the high temperature regenerant (acid) is also provided from such a lining. There is a possibility that an increase in the elution amount of the metal component due to the above will occur as well. On the other hand, in the present embodiment, the above-described configuration can prevent the high-temperature regenerant from coming into contact with the lining provided on the tank 10 and other members other than the pipe 20, that is, its The amount of metal components eluted from such members can be reduced as much as possible. As a result, the metal concentration in the ultrapure water produced by the ultrapure water production apparatus 1 can be reduced as much as possible.

Groundwater is preferably used as the cooling medium for the heat exchanger 41, but since the heat exchanger 41 may be blocked by the precipitation of hardness components and silica contained in the groundwater, for example, semiconductor devices and liquid crystal devices. Circulating water in the manufacturing process may be used.

1 Ultrapure water production equipment 2 Ion exchange resin tower 3 Regeneration agent supply equipment 10 Tank 11 Inner wall 12 Outer wall 13 Heat shield 20 Piping 21 Inner pipe 22 Outer pipe 23 Heat shield 30 Air flow means 31 Air inlet 32 Air outlet 33 Rectification Plate 41 Heat exchanger 42 Temperature sensor 43 Drain valve S Hollow part

Claims (11)

A regenerator supply device that supplies a regenerator that regenerates the cation exchange resin to an ion exchange resin tower filled with a cation exchange resin.
A tank that is installed outdoors and stores the regenerant,
A pipe connecting the tank and the ion exchange resin tower,
A regenerating agent supply device including a temperature control mechanism for controlling the temperature of the regenerating agent supplied from the tank to the ion exchange resin tower through the piping. The regenerative agent supply device according to claim 1, wherein the temperature control mechanism has a heat shield material that thermally shields the inside of the tank from the outside. The tank has a double wall structure including an inner wall and an outer wall.
The regenerative agent supply device according to claim 2, wherein the heat shield is arranged between the inner wall and the outer wall. The regenerative agent supply device according to claim 2, wherein the heat shield is arranged so as to cover the outer periphery of the tank. The regenerative agent supply device according to any one of claims 1 to 4, wherein the temperature control mechanism has a heat shield material that thermally shields the inside of the pipe from the outside. At least the part of the pipe arranged outdoors has a double pipe structure composed of an inner pipe and an outer pipe.
The regenerative agent supply device according to claim 5, wherein the heat shield is arranged between the inner pipe and the outer pipe. The regenerative agent supply device according to claim 5, wherein the heat shield material is arranged so as to cover the outer periphery of a portion of the pipe arranged outside. The tank has a double wall structure including an inner wall and an outer wall.
The regenerative agent supply device according to claim 1, wherein the temperature control mechanism includes an air flow means for circulating air between the inner wall and the outer wall of the tank. The air flow means is provided in a hollow portion between the air inlet provided in the lower part of the tank, the air outlet provided in the upper part of the tank, and the inner wall and the outer wall, and the air inlet and the said. The regenerative agent supply device according to claim 8, further comprising a straightening vane forming a spiral passage communicating with an air outlet. The temperature control mechanism is provided in the pipe to cool the regenerating agent, and the temperature of the regenerating agent flowing in the pipe is detected downstream of the heat exchanger in the pipe. The regenerating agent supply according to any one of claims 1 to 9, further comprising a temperature sensor to be used and a drainage means for discharging the regenerating agent flowing in the pipe to the outside based on the detection result of the temperature sensor. apparatus. The regenerating agent supply device according to any one of claims 1 to 10, wherein an ion exchange resin tower filled with a cation exchange resin inside and a regenerating agent for regenerating the cation exchange resin are supplied to the ion exchange resin tower. And, with an ultrapure water production device.

Images